VM에서 USB Storage attaching 및 detaching 하기 – 영문

Summary

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This document provides a script for the purposes of automating the procedure of attaching and detaching USB mass storage devices from a given VM on XenServer.

 

This method is particularly useful in environments where USB storage such as removable hard disks is used for storing backups and are rotated on a regular basis.

 

Requirements

 

The following is required:

1. XenServer Host.
2. XenCenter installed on the host running the backup software.
3. USB Mass-storage device recognized by XenServer.
4. The usbmount.bat batch script.

 

Background

 

In some environments, USB mass storage devices are used for the purposes of backups. In order for this to be effective, the USB storage device is rotated and removed from the server after a backup.

 

Ordinarily, this process requires you to first confirm that the disk is not in use and then manually perform the detach operation. Similarly, when the disk is re-attached to the server, the storage must be again manually attached to the virtual machine.

 

Many different backup programs provide the ability to execute programs before and after a backup and using XenServer’s XE utility, it is entirely possible to automate this procedure.

 

Solution

 

1.    Install XenCenter

 

The batch program for handling the operation depends on the XE.EXE utility, a command-line interface client for executing commands on XenServer hosts. This utility is included as part of the XenCenter installation, hence XenCenter must be installed on the host on which you intend on running the utility.

 

If you choose to install XenCenter to a location other than C:\program files\citrix\XenCenter\ please take note of the exact installation path as you will need to modify the batch script accordingly.

 

2.    Modify the usbmount.bat script

 

Using a text editor such as Notepad, edit the usbmount.txt script according to your requirements. The following attributes must be set:

 

Set the username, password and address (IP or hostname) of your XenServer host:

 

SET XE_USERNAME=root

SET XE_PASSWORD=CHANGEME

SET XE_SERVER=xxx.xxx.xxx.xxx

 

Determine the UUID of the Storage Repository that corresponds with Removable Storage. You can determine this by running the following from within your XenServer host console:

xe sr-list name-label=Removable\ Storage

 

Once you have the UUID of the Removable Storage, make the change to the script:

REM Removable Storage Repository UUID

SET REMOVABLE_SR_UUID=CHANGEME

 

Next, determine the UUID of the virtual machine you wish to attach the storage to. To do this, run:

xe vm-list

 

With the UUID of the VM, make the change to the script:

 

REM UUID of the VM you wish to attach the USB storage to

SET VM_UUID=CHANGEME

 

Finally, you need to set the device order. It is important to ensure that there is no overlap and this is done by looking at the number of devices attached to the VM. For example, if only one storage device is currently being used (e.g. virtual hard disk), the next device name to use will be hdb.

 

REM Device name/order on the VM (e.g. hdb, hdc, hdd…)

SET DEVICE_NAME=hdb

 

3.    Run or Schedule the Batch Program

 

Once you have made the changes to the batch program, test it by running it from a Command Prompt window. Note that the utility requires a parameter, otherwise it will exit.

 

To attach the USB storage device to the VM, run:

usbmount.bat attach

 

To detach the USB storage device from the VM, run:

       usbmount.bat detach

Listing of USBMOUNT.BAT

 

@ECHO OFF

setlocal

REM Attach a USB flash device to a specified VM on XenServer 4.x

 

REM ————- EDIT THE OPTIONS BELOW TO SUIT YOUR ENVIRONMENT ————-

 

REM XenServer Credentials

SET XE_USERNAME=root

SET XE_PASSWORD=CHANGEME

SET XE_SERVER=xxx.xxx.xxx.xxx

 

REM Removable Storage Repository UUID

SET REMOVABLE_SR_UUID=CHANGEME

 

REM UUID of the VM you wish to attach the USB storage to

SET VM_UUID=CHANGEME

 

REM Device name/order on the VM (e.g. hdb, hdc, hdd…)

set DEVICE_NAME=hdb

 

 

REM —————————————————————————

 

REM XenCenter Path

SET XE_CENTER_PATH=C:\program files\citrix\XenCenter\

 

REM XE Binary and Baseline Parameters

SET XE_EXEC=”%XE_CENTER_PATH%\xe.exe” -s %XE_SERVER% -u %XE_USERNAME% -pw %XE_PASSWORD%

 

REM Temporary working file

SET TEMP_FILE=%TEMP%/xs-usbmount.tmp

 

 

REM ———— DO NOT EDIT BEYOND THIS LINE —————-

 

IF “%1″==”ATTACH” GOTO ATTACH_STORAGE

IF “%1″==”DETACH” GOTO DETACH_STORAGE

 

REM No parameters

echo Usage USBMOUNT.BAT ^<ATTACH ^| DETACH^>

GOTO END

 

 

:DETACH_STORAGE

%XE_EXEC% vdi-list sr-uuid=%REMOVABLE_SR_UUID% params=vbd-uuids –minimal > %TEMP_FILE%

SET /P VBD_UUIDS= < %TEMP_FILE%

 

IF “%VBD_UUIDS%”==”” GOTO NOT_BOUND

%XE_EXEC% vbd-unplug uuid=%VBD_UUIDS%

%XE_EXEC% vbd-destroy uuid=%VBD_UUIDS%

echo.Storage Detached

 

GOTO END

 

 

:ATTACH_STORAGE

 

REM See if the storage is already bound to a VBD

%XE_EXEC% vdi-list sr-uuid=%REMOVABLE_SR_UUID% params=vbd-uuids –minimal > %TEMP_FILE%

SET /P VBD_UUIDS= < %TEMP_FILE%

 

IF NOT “%VBD_UUIDS%”==”” GOTO ALREADY_BOUND

 

%XE_EXEC% vdi-list sr-uuid=%REMOVABLE_SR_UUID% params=uuid –minimal > %TEMP_FILE%

SET /P VDI_UUID= < %TEMP_FILE%

 

%XE_EXEC% vbd-create vm-uuid=%VM_UUID% device=%DEVICE_NAME% vdi-uuid=%VDI_UUID% –minimal > %TEMP_FILE%

SET /P VBD_UUID= < %TEMP_FILE%

 

%XE_EXEC% vbd-plug uuid=%VBD_UUID%

 

echo.VBD UUID attached as: %VBD_UUID%

GOTO END

 

 

:ALREADY_BOUND

echo.Removable storage already attached to a VM – aborting.

GOTO END

 

:NOT_BOUND

echo.Storage device not bound to any VMs – aborting.

GOTO END

 

:END

endlocal